The present invention relates to a control system and pertains particularly to linkage means for simultaneous control of the engine and transmission of a lift truck or the like from a common foot pedal.
Lift trucks and other similar article handling vehicles normally require that an operator be able to manipulate the vehicle at the same time he is manipulating the article handling implements. The controls of such vehicles are normally arranged such that the steering of the vehicle and the manipulation of the article handling means is controlled by the operator's hands. With such arrangements, it is necessary that the operator be able to control both direction and speed of the vehicle with his feet. It is particularly desirable that the direction and speed of the vehicle be controlled with a single foot to free the other foot for use in operating other necessary pedal actuated devices such as brakes and the like.
Although other systems have been proposed in prior art for control of such vehicles, such proposed prior art systems suffer from one or several disabilities. In particular, control of an engine governor usually involves springing means to return the engine governor to a neutral position. Although some systems have incorporated balancing means to overcome the force imposed on the operator's foot pedal by the governor return spring, such systems have required extensive bell cranks and linkage arrangements and the like. Other systems proposing various other schemes to achieve the required motion, have failed to incorporate the balance means in the linkage.